Examples of automobiles include gasoline automobiles using gasoline and diesel automobiles using light oil. In addition to these, gas engine automobiles and fuel-cell vehicles using a fuel gas, such as a compressed natural gas (CNG) or compressed hydrogen, have been known. In the gas engine automobile or the fuel-cell vehicle, the fuel gas is stored in, for example, a high-pressure tank, and the stored high-pressure fuel gas is supplied to a gas engine or a fuel cell (fuel gas consuming unit) through a fuel gas supplying and filling system. Known as the fuel gas supplying and filling system is, for example, a fuel supply apparatus of a gas engine in PTL 1.
The fuel supply apparatus of the gas engine described in PTL 1 includes a fuel injection valve, and the fuel injection valve and a bomb (high-pressure tank) are connected to each other by a pipe. On a passage of this pipe, a main stop valve, a regulator, and a low-pressure fuel shutoff valve are provided in this order from the bomb side. A fill passage on which a check valve is provided is connected to the passage so as to be closer to the bomb than the main stop valve (to be specific, located upstream of the main stop valve). The check valve allows the fuel gas to flow through a filling opening, formed at a tip end of the fill passage, into the passage and blocks the opposite flow of the fuel gas.
In the fuel supply apparatus of the gas engine configured as above, when the high-pressure fuel gas is supplied through the filling opening, the fuel gas opens the check valve to flow into the pipe and is then introduced to the bomb to be stored in the bomb. With this, the fuel gas can be filled in the bomb.